This invention pertains generally to high-temperature and high-strength plastics and in particular to polyphthalocyanine plastics.
The polyphthalocyanines disclosed and claimed in U.S. Pat. Nos. 3,993,631 and 4,067,860 by James R. Griffith and Jacques G. O'Rear have numerous advantages over polyepoxies and other high-temperature and high-strength plastics. These compounds can withstand temperatures up to 200.degree. C. with no degradation, up to 250.degree. C. with slight degradation, and up to 350.degree. C. with moderate degradation. As adhesives, they remain effective at temperatures above 200.degree. C.
Polyphthalocyanines are prepared by heating an orthodicyanophenyl diamide at a temperature from 200.degree. C. to 240.degree. C. or by mixing this diamide with a metal or salt. Generally, cures with a higher temperature and/or with a salt or metal are quicker, but no cure time is less than about twenty four hours. Many polyphthalocyanines require cure times as long as forty eight hours.
Polyphthalocyanines which are prepared by admixing a metal or salt with a bisorthodicyanophenyl diamide often have the problem of trapped gas in the final polymer. This problem is particularly prevalent with salts.
Many of the known metals and salts do not disperse evenly throughout the bisorthodicyanophenyl diamide and consequently cause the diamide to polymerize unevenly. The resulting polymer has poor properties, e.g., weakness on account of a lack of homogeneity. This problem is minimized by a careful mixing of the salt or metal. This problem is particularly prevalent among salts. In fact, some salts, e.g., stannous chloride have not been successfully reacted with a bisorthodicyanophenyl diamide to form a useful polyphthalocyanine.
Like most plastics, these compounds are not self-extinguishing. This disadvantage is not as great as it is with other plastics, such as, polyepoxies on account of their exceptional thermal stability and heavy charring. However, a problem does exist because these compounds do burn at temperatures found in many fires, e.g., around 1000.degree. C. or more.